A typical lawn sprinkling system has lateral flow lines buried in various parts of the lawn, plant beds, and the like. One or more risers or sprinkler heads connect to each lateral flow line and extend upward to level at or above the surface of the ground. The sprinkler heads include types that pop up when supplied with water pressure as well as types that are stationary and have orifices located above the ground.
A solenoid operated valve is connected to the various flowlines for selectively applying water pressure for a timed interval. A controller controls the solenoid valve to automatically supply water pressure. The user can adjust the days for watering as well as the duration of timed intervals and the particular flow lines to receive water pressure.
If one of the heads breaks, an excessive amount of water will flow through the broken head for each timed interval. Because the controller is automatic and the owner not always present during watering intervals, the owner may not realize for some time that the head is broken. Various patents disclose devices to remedy excessive water discharge in the event of a sprinkler head breakage, but improvements are desired. For example, the safety valve member in some of the devices is located above ground in the riser. Typically, a failure is caused by breakage of the riser, and in these types of devices, the safety valve must be replaced after one failure.